Conventionally, antennas include separate components for transmitting and receiving electromagnetic energy, such as a first antenna for transmitting electromagnetic energy and a separate and distinct second antenna for receiving electromagnetic energy. As will be appreciated, such conventional antenna assemblies are not well suited for applications where space is at a premium, or where maximum coupling is required between an antenna and a transponder for simultaneous transmission and reception. Systems having these performance requirements include, for example, electronic article surveillance (EAS) systems and other systems in which simultaneous bi-directional communication is required.
Other conventional antennas including a single component for both transmitting and receiving electromagnetic energy typically have a mechanism for switching an antenna between a signal generator and a receiving mechanism, such that, at any particular time, the antenna either transmits or receives electromagnetic energy. In other words, these conventional antennas cannot simultaneously transmit and receive electromagnetic energy. As will be appreciated, such conventional antennas are not suited for use in applications where the simultaneous transmission and reception of electromagnetic energy by a single antenna are required.